Problem with the home button (semi-working)

So I have an iPhone 8 Plus, which has a home button that is behaving abnormally. A screen replacement was conducted. During the iOS upgrade (the Apple logo and progress bar screen), the home button would click normally. Upon reaching the Hello screen, it stopped clicking. Setting it up towards the Touch ID section, I get the “Unable to read this fingerprint. Try again using a different finger.” However, after that messaged, the button started clicking again. Single, double, and even holding down starts working. (This is the original home button I assume, by the way). This problem was happening on both the old cracked screen and the new.

Putting the screen to sleep and waking it up, the home button stops clicking. Setting up Touch ID again, it failed like before, while also bringing back the click functionality until the screen is put to sleep. Reinstalled iOS through both Recovery and DFU mode, still has the same problem.

Has anyone experienced this problem? Or this is an unusual case? Or perhaps the home button has been damaged? The flex cable seems to be fine from the looks of it.

Thanks!